bash check file == string code example

Example 1: bash check if string in file

Just use grep with flags 'F' (fixed string), 'x' (exact match) and 'q'
(quiet output) in order to check if a word string is in a file
if grep -Fxq "string" file.txt; then #do some code...#; fi

Example 2: test string equality bash

strval1="Ubuntu"
strval2="Windows"

#Check equality two string variables

if [ $strval1 == $strval2 ]; then
  echo "Strings are equal"
else
  echo "Strings are not equal"
fi

#Check equality of a variable with a string value

if [ $strval1 == "Ubuntu" ]; then
  echo "Linux operating system"
else
  echo "Windows operating system"
fi